Completion Method Featuring a Thermally Actuated Lock Assembly for a Telescoping Joint

ABSTRACT

A completion method involves a telescoping joint in the completion string that needs to be locked when pumping fluid through it as part of the completion method. The joint is locked with two locks and one is thermally activated using a shape memory locking member to handle the stresses from component contraction. The setting of the thermally actuated lock occurs when the temperature is lowered during pumping. At other times the temperature of well fluid defeats the thermal lock leaving a non-thermal lock actuated until such time that the telescoping joint can be used in production. The non-thermal lock is defeated so allow normal telescoping action during production. The non-thermal lock is defeated with string manipulation or pressure or other ways depending on its design.

FIELD OF THE INVENTION

The field of the invention is completion methods where telescopingcomponents need to be held together during some operations that alsoinvolve other steps that would defeat a single mechanical orhydraulically released lock and more particularly an applicationinvolving a telescoping joint.

BACKGROUND OF THE INVENTION

Some completion assemblies require a telescoping joint to be operativewhen production begins but for the purposes of the completion the jointneeds to retain a fixed length. During completion operations can occurthat place significant stresses on a lock that for example operates on ashear principle. Certain pumping operations introduce significantlycooler fluids into the completion assembly that would defeat shear pinsor rings or cause unwanted axial translations. Various mechanicalmanipulations are also accomplished during the completion orapplications and removal of pressure such that a single lock that isdefeated with stress, movement or pressure cycles would releaseprematurely. What is needed and provided by the present invention is adual locking system so that a telescoping joint can be retained by athermally actuated lock that locks when a cool fluid is pumped thatwould cause significant thermal stresses of contraction and at the sametime that very same lock releases after the cool fluid pumping ceases sothat when the joint is needing to telescope it can do so. Thenon-thermal lock can be defeated as needed, either before or afterpumping operations, for normal telescoping operation.

Thermal locks using shape memory components are described in U.S. Pat.No. 8,366,368; 6,508,437; 20100215424 and 20100229610.

The method contemplates a pair of locks where there is a thermallyoperated lock coupled with a non-thermally operated lock. Both operateon a telescoping joint to hold the telescoping components in a fixedrelation for running in. As the joint is exposed to warm well fluids thethermally operated lock releases leaving the joint still locked with thenon-thermal lock so that various steps in the method that can involvestring manipulation or application or removal or pressure can takeplace. When it comes time to pump relatively cold fluid through thejoint that would create substantial stress on the non-thermal lock tothe point of likely failure, the drop in temperature engages the thermallock so that the non-thermal lock is protected. Alternatively thepumping can cause unwanted translation if the non-thermal lock wasalready defeated. Translation induced by pumping could affect toolpositions or, in case of a system shown in U.S. Pat. No. 8,403,064, thetranslation could prematurely activate another device. Subsequentremoval of the cold fluid allows the warming of the thermal lock to thepoint of defeat after the stress induced by the cold pumping fluiddisappears. At that point when the telescoping joint is needed to beoperative the non-thermal lock can be defeated such as by mechanicalmanipulation or applied pressure. As stated above, the non-thermal lockcan also be defeated ahead of the pumping. These and other aspects ofthe present invention will be more apparent to those skilled in the artfrom a review of the detailed description of the preferred embodimentand the associated drawings while recognizing that the full scope of theinvention is to be determined from the appended claims.

SUMMARY OF THE INVENTION

A completion method involves a telescoping joint in the completionstring that needs to be locked when pumping fluid through it as part ofthe completion method. The joint is locked with two locks and one isthermally activated using a shape memory locking member to handle thestresses from component contraction. The setting of the thermallyactuated lock occurs when the temperature is lowered during pumping. Atother times the temperature of well fluid defeats the thermal lockleaving a non-thermal lock actuated until such time that the telescopingjoint can be used in production. The non-thermal lock is defeated soallow normal telescoping action during production. The non-thermal lockis defeated with string manipulation or pressure or other ways dependingon its design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view that shows the movement of the thermal lockbetween locked and unlocked positions on the telescoping joint;

FIG. 2 is a detailed view of the thermal lock in the unlocked position;and

FIG. 3 is the view of FIG. 2 with the thermal lock in the lockedposition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows components 10 and 12 that telescope with respect to eachother with seal 14 maintaining the integrity of the connection. Thetelescoping joint can be part of a bottom hole assembly such asdescribed in U.S. Pat. No. 8,403,064 whose disclosure is incorporatedhere by reference as if fully set forth. A thermal lock assembly 16 ismade from a series of curved segments 18 that sit in a conforming grooveor grooves 20 in component 12. Optionally, the illustrated design can bereversed from the orientation of FIGS. 2 and 3 within the scope of theinvention. In the reverse orientation the segments can be in component10 instead of 12 and the mating profiles 22 and 24 would be reversedfrom the manner displayed in FIGS. 2 and 3. Preferably the profiles 22and 24 are portions of a thread pattern although other projection anddepression combinations can be used. This includes the segments 18simply changing dimension to extend into a recess in the opposingmember. The segments are made of a shape memory alloy that below thecritical temperature is in the locked position of FIG. 3 but above thecritical temperature reverts to the unlocked position of FIG. 2.

Also shown in FIG. 1 is a non-thermal lock 25 which in one case is oneor more shear pins that straddle components 10 and 12. The non-thermallock 25 holds the components 10 and 12 against relative movement duringother operations but is lacking in sufficient strength to resist thethermal stresses when fluid is pumped through passage 26 while there isstill a need for proper spacing out for the components 10 and 12 toremain locked against relative axial movement.

In operation, the components 10 and 12 are at ambient temperature whenrun into a well. The thermal lock 16 is in the FIG. 3 position. Asexposure to warm well fluids continues the thermal lock 16 releases asin the FIG. 2 position as the temperature exposure above the criticaltemperature has the segments in the enlarged dimension of FIG. 2. Atthis time the non-thermal lock is still functional and normal operationsof the method can continue without fear of changing the length of thetelescoping connection from relative axial movement between thecomponents 10 and 12. Certain jarring loads can still be resisted by thenon-thermal lock. However, as the fluid pumping starts, so does theaxial shrinkage. Since it is a thermal effect it takes some time tohappen. While component shrinkage starts on the outset of cooling, thenon-thermal lock 25 can resist that level of stress until such time asthere is enough dimensional change for the segments 18 so that profiles22 and 23 engage. From that point on for the duration of the fluidpumping, the thermal lock through components 18 takes the shear loading.The capacity of the thermal lock is orders of magnitude above thenon-thermal lock and the stress imposed during pumping the cooler fluidwould otherwise cause the non-thermal lock 25 to fail if the thermallock assembly 16 were not in the lock position of FIG. 3. After thepumping operation the non-thermal lock 25 is still operational.Eventually when all other steps requiring the components 10 and 12 tohold their relative positions are done then the non-thermal lock isovercome with force, string manipulation or pressure and the telescopingjoint is put into service where components 10 and 12 can slide axiallyrelative to each other. While the latter is true for a shear screwembodiment, another embodiment could have a non-thermal lock that isdefeated before the pumping operation. This non thermal lock could beactivated by pressure or tool string manipulation. The reason thisalternate works is that there are not any loads, other than the thermalcontraction which could cause the, in this case, expansion joint totranslate.

Some applications of the above described system can be an alternative toshear to release packers or anchor or snap latches.

The above description is illustrative of the preferred embodiment andmany modifications may be made by those skilled in the art withoutdeparting from the invention whose scope is to be determined from theliteral and equivalent scope of the claims below.

I claim:
 1. A completion method, comprising: providing a bottom holeassembly with a telescoping joint having relatively movable componentsthat need to be axially locked before being put into production;providing a thermally actuated lock in tandem with a non-thermallyactuated lock on the telescoping joint between said components; pumpingfluid through said telescoping joint that is colder than surroundingwell fluid; using said pumping to set the thermal lock between saidcomponents; unlocking said locks before production.
 2. The method ofclaim 1, comprising: unlocking said non-thermal lock after said pumping.3. The method of claim 1, comprising: unlocking said non-thermal lockbefore said pumping.
 4. The method of claim 1, comprising: using a shapememory material for a locking member in said thermal lock.
 5. The methodof claim 1, comprising: using at least one segment that changesdimension with temperature disposed between said components as saidthermal lock.
 6. The method of claim 5, comprising: providing a surfacetreatment on said segment to selectively engage a mating pattern on anopposing component.
 7. The method of claim 5, comprising: allowing saidsegment to enter a recess in an opposing component when changingdimension.
 8. The method of claim 1, comprising: disposing said segmentin an annular space between said components.
 9. The method of claim 5,comprising: using a shape memory alloy for said segment.
 10. The methodof claim 1, comprising: running in with said thermal lock engaging saidcomponents.
 11. The method of claim 10, comprising: using well fluidtemperature to release said thermal lock from one of said components.12. The method of claim 11, comprising: reducing temperature in saidcomponents with said pumping so as to engage said thermal lock to holdsaid component together.
 13. The method of claim 12, comprising:defeating said non thermal lock with force, string manipulation orpressure before said reducing temperature.
 14. The method of claim 12,comprising: defeating said non thermal lock with force, stringmanipulation or pressure after said reducing temperature.
 15. The methodof claim 5, comprising: making said at least one segment a c-ring. 16.The method of claim 5 comprising: providing a plurality of segments assaid at least one segment.
 17. The method of claim 6, comprising: usinga thread or grooves as said surface treatment.
 18. The method of claim1, comprising: making said components part of a packer or an anchor orsnap latch.